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SMPS with negative feedback?

eem2am

Aug 3, 2009
429
Joined
Aug 3, 2009
Messages
429
Hello,

I have implemeneted an external error amp with this 12V, 10A buck converter with an op amp (U3) followed by an NPN (Q1).

The error amplifier feedback is taken into the "non-inverting input" of the op amp due to the fact that the NPN (Q1) does an inversion.

Is this OK?......i always thought feedback had to go to the inverting input of the error amp?
(the error amp is external as this buck will be paralleled with ten other bucks all feeding the same 100A load...just one error amp feeds all controllers)

Schematic (also provided in pdf)
http://i39.tinypic.com/317ccx5.jpg


LTspice sim also attached
 

Attachments

  • INTERLEAVED BUCKs tl431typ..pdf
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  • INTERLEAVED BUCKs tl431typ..xxx.txt
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